Telephone-transmitter.



PATENTED JULY 10, 1906.

E. C. BREWER. TELEPHONE TRANSMITTER.

APPLICATION FILED JAN.19. 1906.

UNITED STATES PATENT oFFIoE.

EVERETT C. BREWER, OF ST. LOUIS, MISSOURI, ASSIGNOR OF ONE-HALF TOWILLIAM H. N OLKER,

OF ST. LOUIS, MISSOURI.

No. 825,635. I

Specification of Letters Patent.

Patented Tin 10, 1906.

Application filed January 19,1906. Serial No. 296,782.

To all whom it may concern.-

Be it known that I, EVERETT O. BREWER, a citizen of the United States,residing in the city of St. Louis, inthe State of Missouri,have

invented certain new and useful Improvements in Telephone-Transmitters,of which the followin is a full, clear, and exact description, re erencebeing had to the accompanying drawings forming part of thisspecification.

My invention relates'to the provision of means in atelephone-transmitter whereby germ-laden moisture from the breath ofdiseased ersons using a telephone may be prevente from lodging in thetransmitter, the improvement consisting, essentially, in fur nishing aseal for the, exposed portion of the transmitter in front of the usualdiaphragm and providing against the existence of any cavity in whichgerms ma lodge and from which they cannot be read' y removed.

Figure I is a section of a telephone-transmitter, showing my inventionap lied thereto. Fi II is a view,'partly in out elevation an partly incross-section, of the transmitter with mysealing member located there-Fig. IIIis a perspective view of the sealmg member.

A designates the casing of a telephonetransmitter, which contains theusual diaphragm B, its seating-ring C, and other appurtenances of atransmitter, for which no invention is herein claimed. 7

1 desi ates a secondary dia hragm that is place in front of the mainiaphragm B, but spaced apart therefrom to provide anairchamber betweenthe two diaphra in order that vibration established in the's'econdarydiaphra by waves from the human voice may e imparted to. the maindiaphragm. The secondary diaphragm is preferably held in position by aclamp ring 2, having a rearwardly-extending flange interiorly screwthreaded'to engage ascrewthread on the exterior of the seatring thatbears against the main diaphragm 3 is a acking-band, preferably ofrubber, that is tted to the secondary diaphragm and which is adapted tobe clamped between the clamp-ring 2 and the main-diaphra m seat-ring C,this packin -band being so 0- cated that it extends to tine edge of theaperture in the clamp-ring 2 to avoid the existence of any cavitybetween said ring and the secondary diaphragm in which moisture maylodge. The edge of the aperture of the clamp-ring may therefore bereadily cleaned from time to time. As there is no inaccessible cavityinto which moisture from the breath may gain entrance, the transmitter1s rendered of-a thoroughly sanitary nature.

The secondary or sealing diaphragm is of an suitable impervious flexiblematerial capahle of preventing the passage of molsture therethroughsuchas mica, celluloid, metal or alloys of metals that are susce tible ofv1- bration under the waves of sound 0 the human voice and saidsecondary diaphragm, While acting as a sealing member for the transmtter, does not detract from the efficiency of the instrument in which itis present. This ab-. sence of detraction isdue to the secondarydiaphragm serving as an initial sound-wavereceivinglg member and by itsvibration causing simi ar vibration of the main diaphragm correspondingto that which would occur if the main diaphragm Was used alone.

I claim as my invention 1. In a telephone-transmitter, the combinationof a casing, a main diaphragm withi n said casing, a seat-rin againstwhich said ma n diaphragm rests, a 0 am -ring fitted to said seat-ring,and a secon ary diaphragm located between said clamp-ring and seat-ring.

2. In a telephone-transmitter, the comb nation of a casing, a maindiaphra within said casing, a seat-ring against w 'ch said maindiaphragm rests, a clamp-ring fitted to said seat-rin a secondarydiaphragm located between sai clamp-rin and seat-ring, and asacking-band surroun ing said secondary iazphragm andheld. between saidseatr1ng an clamp-ring.

, EVERETT O. BREWER.

- Inpresenceof- E. S. KNIGHT, NELLIE V; ALEXANDER.

